代码需要优化！！！！！！

Question

public void exportArrearDatail(HttpServletRequest request, HttpServletResponse response){
    String templateId = request.getParameter("templateId");
    String fileNames = request.getParameter("fileName");
    String fileName = null;
    try {
        fileName = java.net.URLDecoder.decode(fileNames, "UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }
    String areaId = request.getParameter("areaId");
    String dataType = request.getParameter("dataType");
    ExcelUtil excel = new ExcelUtil();
    Map<String, Object> map = new HashMap<String, Object>();
    map.put("templateId", templateId);
    if (areaId != null && !areaId.equals("")) {
        map.put("areaId", areaId);
    }
    if ("effective".equals(dataType)) {
        map.put("effective", "'有效'");
    }
    excel.createBookAndSheet(false, "sheet1");
    excel.writeRow(0, "查询号码", "设备状态", "商品名称", "欠费账龄", "欠费金额",
            "计费类型", "计费标签", "家长姓名", "区域名称", "学校名称", "班级名称", "学生姓名",
            "计费号码", "登录账号");

    int count = arrearAnalysisService.countUserNum(map);
    if (count > 0) {
        List list = new ArrayList();
        ArrearInfo arrearInfo = null;
        int rowNum = 1;
    //就是下面这个循环
    //我试了下就是参数里面的10000是每页显示的数字，如果超出10000它也不会生成第二页
    //用什么值能替换它让它不是固定的 ，而是跟着总数走的
        for (int row = 0; row < count/10000; row += 10000) {
            Page<ArrearInfo> page = arrearAnalysisService.getArrearInfoByPage(map, row*10000, 10000, "arrearAmount", SqlOrderEnum.DESC.getAction());
            list = page.getList();
            for (int i = 0; i < list.size(); i++) {
                arrearInfo = (ArrearInfo) list.get(i);
                if (arrearInfo == null) {
                    break;
                }
                excel.writeRow(rowNum++, arrearInfo.getPhoneNumber(), arrearInfo.getDeviceStatus(), arrearInfo.getGoodsName(), arrearInfo.getArrearAge(),
                        arrearInfo.getArrearAmount(), arrearInfo.getBillingType(), arrearInfo.getBillingLabel(), arrearInfo.getUserName(),arrearInfo.getAreaName(),
                        arrearInfo.getShoolName(), arrearInfo.getClassName(), arrearInfo.getStudentName(), arrearInfo.getPayNumber(), arrearInfo.getLoginNumber());
            }
        }
    }

    Runtime.getRuntime().gc();
    DownloadUtil.downloadXlsx(response, fileName + "用户信息", excel.getInputStream());
}

Answer 1

这个跟数据量有没有关系，EXCEL的最大储存行数为65536行，你看看有没有超过，还有先用小于万件的数据调试下，看有没有内存溢出的情况发生